Add a db.Dispose before calling Delete on the SQLite database.

On Windows, you are not able to delete a file while there is
still a handle to it open.

OpenSim/Data/SQLite/Tests/SQLiteUserTest.cs

@@ -55,6 +55,7 @@ namespace OpenSim.Data.SQLite.Tests
         [TestFixtureTearDown]
         public void Cleanup()
         {
+            db.Dispose();
             System.IO.File.Delete(file);
         }
     }